50 - 
Several growers have stated that they were of the opinion that the 
dusting with proprietary cube root powders, when the plants were wet with dew, 
had a controlling effect .on the tnrips population. They described the thrips 
infestation as potentially the i';orst in several year-, hut actual damage as 
being smaller than it has been at times in the past. The sprays were applied 
at the rate of ,50 gallons per acre, equalling a dust of three to six pounds 
per acre. Since the dust is applied at the rate of eight pounds per acre, 
a heavy dew might form a toxic mixture, as in the case with the flea beetle* 
This heavier dosage is sudd to have been reported from Australia as effective 
and will be tested next season. 
The South Carolina Agricultural Experiment Station (387) in its 1936 
annual report stated that, upon the basis of recent experimental work, 
rotenone may be recommended for the control of the Mexican bean beetle. 
Slightly superior results have been secured when this product was used us 
a spray, but it may also be used as a du-t when the -proper diluent is used. 
The following formulae have given best results; 
Formulae for Liquid Spray Mixture 
Large quantities 
! T o. 1 Powdered air-floated derris 
or cube root containing 5 
percent rotenone. 
Water 
K'o. 2 Powdered air-floated derris 
or cube root containing 4 oer- 
cent rotencfrre. 
Water 
1-3/4 pounds 
50 gallons 
2-1/4 pounds 
50 gallons 
Small quantities 
1-3/4 ounces 
3 gallons 
2-l/4 ounces 
3 gallons 
Smaller portions of rotenone than the above may be used with good 
results, but the residual effect will not be as great. To obtain good pro- 
tection the insecticide would have to be applied mere frequently. One 
hundred to 150 gallons should be applied per acre at each spraying. 
Formulae for Dust Mistures 
No. 1 Powdered air-flcated derris 
or cube root containing 5 
percent rotenone. 
Talc or inert clay 
To make 
0.75; I dust 
15 pounds 
85 pounds 
To make 
0.50$; dust 
10 pounds 
90 pounds 
